NefMoto

Hello, :)

I'm new here. I want going mafless in my s4 b5 because i'm going to do over 600hp on gtx35 turbo. I read about mafless but i have obscurity. I can disconnect maf and already tune any map? Which map i should tune after doing mafless so that fuel would good? Is the car will work correctly, while map sensor is before throttle plate (not see the vacuum)? I come up with an idea to connect the maf cables to the map sensor connector after the throttle plate and scalling the maf map for this pressure  that ECU would be able to see vacuum beyond closing throttle (would be two map sensors). Whether this would work? If not, how to do the classic mafless in order to my s4 to work properly?

Best regards :)
Mateusz

Standalone ECU. (VEMS, DTA)

I don't want standalone. Standalone take away a lot of facilities that for example have Motronic. My car will be a street car. If I want to have standalone I'd not be writing this post on the forum. :)

There are numerous threads about this on this forum, just search.

You will lose traction control though, just keep that in mind.

If you want the traction control back, I have a solution ;)

I imagine a coding change to supply load after all :)..

I might be academically interested in it... and maybe even empirically since I would love to feed turbos directly from two cone filters instead of screwing around with y-pipe et al.

Could someone write anything like a tutorial? What maps i should tune after mafless (mainly fuel)? And if there is a possibility of tune up the car at closed throttle?

 ??? I wouldn't expect any tutorials if you don't even want to read threads already posted about it man.

That, and if you need a tutorial it's so far out of your league you should attempt something a bit more traditional first.

I've been researching MAFless, and I think I found out how. But I would love to know how you do it if you care to share.

Not for free, sorry.

In almost every thread I read: "Not for free". This is already the world. I wrote "like tutorial". I'm from Poland and certain technical words be tough to me. Thread can be closed i guess because leads nowhere. My poor ideology of two map sensors come to grief. :)

Two MAP sensors will work but requires re-write of ECU code.
Again, not for free :)

You should just put that in your sig :P

Kinda cheeky of you don't you think? Considering the amount I've contributed to the forum.
Yeah sorry, I am not going to spend my time working specifically on something you need for free. I have enough cars to tune for paying customers.

Maybe a little cheeky yes.. but you do say it often :)

No doubt you have contributed greatly, but I just find it a little comical that in many threads you end with "not for free" and it's only been apparent to me recently that you do that (as I have been away from the forum for a while and have been reading threads one after another).

Take it as you wish, my comment was just a little poke no need to get bent out of shape over it :)

mbwiejska12  you can call to me, and i think  you are from poland :)

So how about placing the MAF on one turbo intake and scaling the MAF accordingly for twins, less piping, less code, no ESP hack, etc..

Is it possible, according to my idea, to transfer the MAF to the MAP sensor behind throttle, in intake manifold? I mean plugging cables from the MAF to the MAP sensor. Then it can be tuned using the map MLHFM (Linearization of MAF voltage)? Can it work?

No, that is impossible, you need to write custom code.

Sounds awfully complicated just to remove the MAF.

Why not just run an HPX (or similar) sensor in blowthrough, problem solved and still keep ME7 happy.

what I dont get ist... how does the blowtrough MAF handle the different pressures... I mean how does it recognize if the air blows trough with 1 bar or 2 bar...  the airspeed could be the same at different pressures, but the amount of air is f.e. double...

...suck trough maf have always the same pressure to handle...  (ok, maybe little pressure drop)

The air amount isn't double. It's a closed system so what comes in(at the filter) MUST be the same that goes through the MAF, now the velocity, temperature, etc may have changed but those should all keep, roughly the same MAF reading because the convection of the thermister should be the same. I'd be worried about blow-by oil getting on the thermister and going through MAFs.

I think you didnt get me :-)

Let me explain my thoughts twice.

An inlet side MAF reads air at nearly atmospheric pressure (so to speak) even at lets say 2 bar pressure absolute after turbo. The air trough the maf is measured by its velocity. The faster the more cooling effect to the sensor. The amount of air is given by cooling effect to the sensor and the diameter of the MAF housing = MAF curve.

So you put the same MAF to the pressure side. Sure the amount of air stays the same trough the entire system at the same 2 bar. But now, the MAF sensor is getting air with double density at 2bar. Single density at 1 bar and triple density at 3 bar. How can the MAF sensor handle this, because the velocity of the air maybe the same at different given boost pressures. Is the cooling effect of the air dependent to the air density? Must be I think!?

Noone suggested using a stock sensor, in fact the hpx sensor with the included transfer sheet is preferred as it has been calibrated for this use.

Yes. Absolutely dependent on the air density. Doesn't matter where you put the MAF, 5v max is 5v max

You have to think though, the air may be double the density due to compressing it, but it is not necessarily the same conditions as ambient air. Meaning when air is compressed, it heats up. Hotter air = less dense.

The nature of a hot wire MAF takes into account the air density and temperature.

No question - clear as water  ;)


So from all these points (the following is strongly theoretical):

If I put two identical MAF with identical diameter in the car. One on the inlet side and the other on the pressure side, they both will show the same values across the rev/boost range?

Ah, sorry I was thinking you were saying it wouldn't work. Yes, you're right. The pressure increase brings more mass(higher density) into the equation which gives the air more potential to take heat away from the thermistor. Your convective coefficient for heat transfer goes up with more density. The MAF sensor should definitely come after the intercooler to battle with less tuning changes. I'm not sure if there would be enough delta(T), pre-intercooler, to get a good resolution out of the MAF.

bbax(response 2) - I don't think it will be 100% the same because you'll be flowing air that is slightly warmer than ambient, given that you have a decent intercooler setup. Also, "straightness" of flow comes into account with a blow-through MAF too. You wont want any turns shortly before and after(although not as critical).

thank you for understanding me  :D

I wasn't the questions if it does make sense with stock sensor, or doubt it will work...  it was only to clear my last questions about functional working... :)

btt

thx

Neglecting air column turbulence (and any other esoteric effects), yes.

Not only that, but the MAF may have a preferred operating temp range where it is most accurate...

Yea, I was wondering that. I know that there is an IAT sensor on the bottom of the intake manifold and behind the throttle body. Does the ECU calculate a difference between ambient and charge air?

Not the difference, per se, but IAT is used in various calculations throughout ME7

By and large, though, a thin film MAF is self-compensating for the temp of the air passing through it (by design)

I once thought it would be cool to go Mafless... but since using the HPX in blow through (works great for me and friends using it) I don't really see the need.
The blow through setup works very well.

Btw you can buy a module that replaces a MAF sensor with 2 x MAP sensors (you need 2 sensors - one for ambient, one for boost) and provides a "MAF like" 0-5V output.
I'll find the link to it later.

That's exactly the sort of thing the OP was trying to do.

Option 1:

$399 - http://www.maftpro.com/tproinfo.shtml

Hmmmm I just realized that unit has "WOT AFR Tracking"
Hookup a Wideband to it and it will adjust the maf output in realtime to match the AFR you want... wow, cool little unit

holy fuckballs that is sweet. Kinda scary though, not sure if ME7 would appreciate load moving around like that ;)

Might sound cool in theory, but what is the practical improvment over STFT?

Think open loop... not closed loop.... Hello!

Might just have to get one and try it... hehe :-)

Does it need an RPM pickup? throttle plate/accel pedal input?

;D Hello!
 Explain how AFR Tracking differs from Closed loop

 Sensor Monitor & Datalogger:
The Sensor monitor page is used to view various sensor and signal values.   Each button toggles one of the 4 viewed valuse through the following list.

RPM - Engine RPM
MP - Manifold presure (KPA)
DC - Density Compensation (Speed Density Airtemp correction factor)
AFL - AirFlow, Speed Density calculated Grams/Sec
AFI - Airflow Input, If a MAF is connected.
VE - Volumetric Efficiency, from the Speed Density algorithm
FI - Frequency input value
FO - Frequency output value
UT - User Tune. Combined System Scale, AF Tune, Airtemp, and Triggered adjustments
TPS - TPS sensor value
BD - Boost Dutycycle
MT - Manifold Temperature
O2 - Voltage reading on O2 sensor input
FE - Flow Error. If a MAF is conected, this is the % dif, MAF and Speed Density
ASC - Afterstart correction
AFR - A/F Ratio, if a wideband is connected.
CF - Wideband tracking Correction Factor
TAF - Target A/F Ratio

The ME7.1 ecu is only closed loop at low load and part throttle, at WOT you are fully open loop...
So this unit could allow you to use the wideband to stay at an exact AFR during open loop mode on the ecu...

No matter how you look at it, AFR tracking is a closed loop system. Get yourself a wideband ECU instead if you have the urge to go closed loop at WOT.

Sounds like a tautology :P


Not easily done on an ME7.1 car.

If using a wideband ecu aka ME7.5 on a 2.7T V6 was easy... I'm pretty sure many would have done it by now... It's not at all simple or that easy.
Indeed AFR tracking IS closed loop... in a time when the stock ecu is normally open loop... I think that is pretty cool myself.

Exactly.  :) My point was AFR tracking is by definition closed loop.
Use a 7.1.1 if you guys really need WOT closed loop :P

Need is a strong word... i think it just came up in the context of something to play with.

I'd use 7.1.1 if it wasn't such a huge pain to work with. Plus we still don't have a functional ME7checksummer for it.

Care to help? :)

Once you have a bone, you don't let go do you? LOL

I'm making the switch over to 7.1.1. The added resolution sold me.

I'm looking at 7.1.1 checksum now and then but have not had enough time to solve it for you yet. I'm sure there are others out there working on it in silence like I have.
I've also wondered why nobody have reversed Winols plugin or ECUfix code. Surely ECUfix must make a perfect checked bin?

Nope :)

Ouch!

Another issue I've had with the 551R allroad file is after a few revisions, winols will error out, telling me not all the expected checksums were found. It detects 73/74. When that happens, I start over and copy my mods to a fresh version of the file. This is usually after 1-2 checksum corrections.

End of hijack.

There is no 2.7t wideband file or anything even remotely workable AFAIK.

DD, what benefit are you swithing to 7.1.1 for?

Just to be remotely OT, I hate piggyback devices. Maybe I'm a purist, idk.

Honestly, just the map resolution. I'm assuming you've looked through the 7.1.1 files, not enough improvement to warrant a switch?

Honestly, it's been awhile, but I don't remember anything that impressive to make it worthwhile.

yay! more proprietary, closed source, re-invent the wheel for the 50000000th time abandonware, like ECUFix, MTX, ME7Check, etc. etc. etc. !

Imagine my excitement.

What I meant was working to find a solution for your open source.  :)
eg. searching for checksum code in IDApro.

I knew what you meant. Kinda like not wanting to announce anything until the solution was in sight. Nyet's just passionate about open source software.

Passionate's an understatement  ;D

Can't argue with his reasoning though

If no one else gets the checks worked out, I'll get the rest of them once I get back up and running and maybe get some of the other things I'm working on finished.

LOL..

Thank you, in advance! Apologies that I misunderstood you.

Basically: what dd said ...

You can have 6 cyl wideband, but then you won't have boost control. :D

What advantage does the ME7.1.1 allroad R-box have over the RS4 K-box? 


Also, with regards to potential wideband integration, does this post have any relevancy?
http://nefariousmotorsports.com/forum/index.php?topic=1883.msg32973#msg32973

With the mentioned 2.8 24v AUE wideband ME7.1 ECU could one possibly disassemble that ECU, disassemble and RS4 K-box, and splice the fueling structure from the wideband ECU into the K-box, and re-compile?  It would obviously be a lot more complicated than simply 'splicing' in code, but is something like that even functionally feasible?

I'd think the loss of boost control would outweigh the potential benefits of wideband fueling. I'd love to get it done. As for the benefits of using 7.1.1 over the rs4 flash, Honestly I'm not sure. I think it all becomes personal preference. Take a look at the files. :)

Well, that's what I'm asking with regards to the AUE file, could one potentially splice in the wideband lambda control into a file that has boost control?

And regarding the  ME7.1.1, I haven't taken a look yet, and I'll check it out myself, but if better load resolution is the only reason, then it doesn't seem like it's worth the effort to go through and define all of the stuff for that file when the RS4 K0box likely has the same resolution, together with pretty well defined definition files and better starting values for stage 3 and up cars.  Just my thoughts anywho.

This is due to hardware limitations like output/inputs, or other design elements between narrowband/wideband ECU's?

The amount of code that you would have to copy over makes this unreasonable IMO.

Organizing it all so that it fits without disturbing everything else would be challenging.

Also, aren't narrowband o2s 0-1v and widebands 0-5v? Wouldn't the ECU max out at 1v from any signal 1.1-5v?

More than challenging ;D ;D ;D Fuel/lambda code is massive.

Besides, the people without programming knowledge could stop dreaming right now:
Most likely those narrowband ECUS lack the LSU4 CJ110 ic.

Yes but that part is easy... just use an external Wideband  and use the 0-5v out.
That's how other ecu's do it.
If a much cruder and older dsm ecu can be converted to wideband then I think it is doable withe the ME7 as well ;-)